A comprehensive review on bentonite and its applications in petroleum industry

Abstract Bentonite, a smectite clay mineral, is essential in petroleum operations for its swelling capacity, thixotropy, and cation exchange properties. However, its effectiveness in high-salinity and high-temperature environments remains a significant challenge. This review synthesizes advanced engineering strategies to enhance bentonite’s performance for modern petroleum applications. It examines activation methods, including acid, thermal, alkaline, and nanomaterial treatments, and their effects on colloidal stability and rheological properties. The review highlights bentonite’s role in enhanced oil recovery, showing that polymer-clay nanocomposites improve thermal stability and conformance control. Data indicate that adding bentonite can extend polyacrylamide gel lifespan from 37 to 120 days at 100 °C and increase elastic modulus by 40 %. The review also evaluates Iranian bentonite reserves as a case study, analyzing their mineralogy and activation needs. By linking fundamental properties with targeted engineering, this review offers a strategic framework for developing advanced bentonite technologies to support more sustainable and efficient hydrocarbon recovery.